Biotechnology Flashcards
(28 cards)
How is acetic acid manufactured?
- acetobacter
- produced from sugars or ethanol
- obligate aerobes
- grow well at pH<5
How is vitamin C manufactured?
- incomplete oxidation of some higher alcohols and sugars –> acetic acid bacteria
How are antibiotics manufactured?
streptomycetes
How is swiss cheese manufactured?
- propionic bacteria
- produce CO2 and propionic acid during fermentation
What was the first human protein to be commercially produced by bacteria?
insulin (humulin)
List some of the issues with expressing mammalia genes in bacteria
- eukaryotic genes must be put under control of a bacterial promoter
- bacterial genes dont have introns
- codon bias may require edits to the sequence
- many mammalian proteins require post-translational modifications
- protein may be degraded in the host cell
- eukaryotic protein may be toxic to prokaryotic host
What is meant by pathway engineering?
process of assembling a new or improved biochemical pathway using genes from one or more organisms
How is indigo manufactured?
- E.coli
- from tryptophan
What is meant by bioremediation?
microbial clean up of environmental pollutants
What is polyhydroxyalkanoates (PHAs)?
bacterial storage polymer
What is microbial leeching?
using microbes to extract valuable metals from low grade ores
Describe the process of targeted gene mining
- need enzyme capable of degrading a certain pollutant
- find environment polluted with target compound
- isolate and clone DNA from environment
- bacteria containing clones screened for growth on target compound
- cells extracts from potential suspects are tested in vitro
Why is plant tissue culture useful?
- micropropagation
- eliminating systemic viruses
How is molecular breeding carried out?
- find DNA marker closely linked to fruit character
- follow it in the progeny of a cross
- use marker to identify seedlings with desired characteristic
How do we find the markers?
- generate fingerprint of parent plant using random DNA markers e.g SNPs
- find markers linked to phenotype
- check lineage is close
- use markers to identify plants at seedling stage
SNPs = single nucleotide polymorphisms
How can we speed up plant breeding?
- treat plant tissue with enzymes to remove cell wall
- create protoplasts
- fuse protoplasts from different genotypes
- use polyethylene glycol or electric pulse
- tool for creating wide crosses between similar but different species
What is meant by embryo rescue?
- culture embryos that would otherwise die
- create new hybrids
What is taxol?
- potent anti-cancer drug
- binds microtubules
- stops cell division
Describe the process of plant transformation
- assemble transgene in a bacterial plasmid
- transfer to plant genome
- select plants with new traits
How is agrobacterium tumefaciens used?
- plant pathogen - causes crown gall
- bacteria delivers own plasmid DNA into plant genome
- one gene codes for an enzyme to make cytokinin
Describe the process of regeneration of plants
- incubate leaf discs with agrobacterium
- balance cytokinin and auxin to induce callus growth
- add more cytokinin to induce shoot growth
- add more auxin to induce root growth
- transfer to soil and gradually reduce humidity
How is a transgene assembled?
- plant DNA binds to promoter
- plant, animal or bacterial DNA binds to coding region
- splice together to form a transgene
How has rice been engineered to produce beta carotene?
cloned genes from 2 species
phytoene synthase (psy) –> narcissus pseudonarcissus
phytoene destaurase –> erwinia uredovora
What are cereals limited for ?
lysine
